Growth Rates for Large Great White Sturgeon in the Fraser River
(+200cm in length)
Sturgeon is one of the few animals that does not stop growing. There are said to be exceptions, and the growth rate is said to slow, but in general a sturgeon continues to grow. This is why in the early 1900’s Great White Sturgeon were found as long as 20 ft in the Fraser River. Due to overfishing and a general lack of environmental impact, these giants are no longer seen. However, there are still White Sturgeon 9 to 13 ft in length.
Yves Bisson has been a Fraser River Sturgeon fishing guide since 2001. During this time, he has advocated for safe handling and conservation of this prehistoric fish. Over the past 20 years, captain Bisson has been responsible for scanning / tagging 20,000+ sturgeon as part of a comprehensive conservation effort.
Fish caught have ranged from 26cm to 344cm and everything in-between.
Growth rates were measured from 50 sturgeon of at least 200cm measured from tip to fork along the medial line. Each of these fish were caught at least twice times prior and over a period of at least 3 years, to allow for a larger overall growth and more accurate assessment.
Time frame between the first and last measurement ranged from 4 to 17 years.
Measured | Parameter |
1.8 | Avg growth rate (cm/yr) |
1.2 | Standard Deviation (cm/yr) |
4.9 | Max growth rate (cm/yr) |
-0.6 | Min growth rate (cm/yr) |
1.8 | Median growth rate (cm/yr) |
49 | Number fish used in study |
225 | Number measurements |
4.6 | Avg # measurements per fish |
The average growth rate for a Fraser River Great White Sturgeon is 1.8cm/year, with 2/3rd of the population ranging from 0.6cm/year to 3.0cm/year. 4 of the 49 fish measured showed less than a 0.5cm/year growth rate.
Comparison of Large Great White Sturgeon Growth Rates with Literature
There is little reliable published data for the growth rate of White Sturgeon above 200cm. This is a very large fish and can only be found in the lower Fraser River and surrounding waters.
The Department of Fisheries & Oceans, only publish estimates up to 170cm in length. (Ref 2: Life Cycle of A White Sturgeon). The Oregonfishinginfo.com Sturgeon Growth chart is likely not relevant at this larger size not seen in American waters.
Growth rates from a common white sturgeon growth chart used in the industry shows a fairly aggressive growth rate in comparison to what was found in our study, all throughout the life cycle. Above 200cm this table estimates a growth rate of 3.0cm / year, vs the 1.8cm/year based on the data used for this study.
In 1963, a comprehensive study of the Age and Growth of the White Sturgeon in the Fraser River was put together by Masters Candidate, Saul Nelson Semakula for the department of Zoology at UBC, however he only had 3 samples above 200cm.